Historically in commercial horticulture, plants have been grown in greenhouses under various forms of lighting, typically HID sodium lamps. These are placed high (typically 2 m) above plants to avoid damage from the large quantities of heat these lamps produce. High density crops, seedlings and other propagated material have typically been grown under fluorescent lamps and stacked vertically in multiple layers. The introduction of light-emitting diode (LED) lighting technology, and in particular the rapid increase in power, efficiency and the reduction in cost, has increased the range of plants viable for commercial horticulture in this multi-layered approach. However, these static multi-layer systems result in plant inaccessibility, as well as restricting available height and lighting apparatus within a fixed structure. In a number of systems a plant is conveyed through static multi-layer systems, which partially improves the access for filling and emptying at each end of the conveyer. However, the height between the layers and the lighting remains inflexible. Further, complex watering systems must be installed and these are inflexible, difficult to maintain and potentially dangerous, particularly alongside lighting that is typically connected to 240 v AC. There is a need to automate this process and reduce the cost of building and operating such multi-layer plant growth systems, whilst taking full advantage of LED lighting technology on a large scale and in a safe environment.